Solution of the direct and inverse problems of the wave reflection from the waveguide fragment filled with a lossy dielectric

Various math method applications for solving the transcendental equation system f1(a,b)-A=0, f2(a,b)-B=0. This system appears when a problem of determination of the complex permittivity from the known coefficient of reflection from the short ended rectangular waveguide fragment filled with a lossy dielectric is solved. Different types of the direct problem formulation which determine the variety of functions f1(a,b), f2(a,b) are considered. The comparison of the obtained results in dependence on the direct problem formulation is presented.